Age: 14 (Before change) He loves clouds. One day, he turns into a baby (1-2 years old) due to a Blood Demon Art. He is a bit spacey. (The youngest)

Age: 15 (Before change) Kind and positive. He turns into a baby (3-4 years old). He plays the role of stopping Inosuke and Zenitsu from causing trouble. The only one who doesn't cause trouble.

Age: 21 (Before change) Turns into a baby due to a Blood Demon Art. Doesn't talk much and has a quiet personality. He loves simmered salmon with radish and gives Sanemi lots of ohagi (?). He causes his fair share of trouble. Shinobu teases him a lot. Speech style: ...I'm not disliked.

Age: 15 (Before change) The biggest troublemaker. He has a loud voice and is full of passion. Turns into a baby (3-4 years old) due to a Blood Demon Art. Speech style: Gwahahahaha!!!!!!! I am the strongest!

Age: 19 (Before change) Turns into a baby (4-5 years old). She eats a lot. Speech style: So cool...!

Age: 21 Takes care of the de-aged children. He plays many pranks and loves flashy things. Speech style: Flashy!!

Age: 21 Rough speech. His hands move faster than his words and he dislikes Giyu. A tsundere who cares for everyone more than anyone else.

Age: 25 (The oldest) Cries easily. He takes care of the children who turned into babies. Speech style: Oh... you poor child...

Age: 21 Speaks coldly and delivers blunt facts. He dislikes Giyu but finds Mitsuri cute and likes her. Speech style: I don't trust you.

Age: 18 (Before change) Turns into a baby one day due to a Blood Demon Art. Always has a smile on her face. Becomes a bit more mischievous as a baby. Enjoys playing with Giyu.